The US defence secretary's move follows a US decision to scale back its commitments to a high readiness force within the alliance.
Related stories
La Tomatina: More than 20,000 people paint Spanish town red with tomatoes
Tornado wreaks havoc in village in southwestern France
King Charles III to visit the Bahamas, Guyana, and Antigua and Barbuda this autumn
Hundreds Feared Dead, Including Foreign Tourists, After Flash Floods in Nepal
Former head of Rwanda's presidential guard dies in prison, his brother says
Pennsylvania man shot dead by cops after returning home from bar and knocking on the wrong door